LOCK RING APPARATUS AND METHOD

APPAREIL DE BAGUE DE VERROU ET METHODE

English Abstract

A lock ring for use as a one way movement restrictor between two telescopingly
arranged tubulars to permit move-ment
in one direction and prevent movement in the other direction of one tubular
relative to the other tubular is described. The
lock ring comprised: a profile having one or more formations formed on the
outer circumference for engagement with a suitable
formation profile formed on the inner circumference of the outer telescopic
tubular; and one or more teeth formed on its inner cir-cumference,
the teeth being adapted to dig into the outer surface of the inner telescopic
member. An apparatus and a method for
setting a downhole anchor is also disclosed.

French Abstract

L'invention porte sur une bague de retenue devant être utilisée en tant que limiteur unidirectionnel de déplacement entre deux tubes montés d'une manière télescopique, afin de permettre le déplacement dans une direction et d'empêcher le déplacement dans l'autre direction d'un tube par rapport à l'autre tube. Ladite bague de retenue comporte : un profil présentant un ou plusieurs éléments formés sur la périphérie extérieure pour venir en prise avec un profil de formation approprié formé sur la périphérie intérieure du tube télescopique extérieur ; une ou plusieurs dents formées sur sa périphérie intérieure, les dents étant conçues pour s'enfoncer dans la surface extérieure de l'élément télescopique intérieur, de telle sorte que le profil, qui présente un ou plusieurs éléments sur la surface extérieure et/ou ladite ou lesdites dents, permet à la bague de retenue d'être poussée le long de la surface extérieure du tube télescopique intérieur quand celle-ci est poussée par le tube télescopique extérieur dans une direction, et de telle sorte que ledit profil est en outre conçu pour enfoncer les dents dans la surface extérieure du tube télescopique intérieur quand la poussée dans ladite direction est supprimée, ou quand ladite bague est poussée par le tube télescopique extérieur dans l'autre direction, dans le but d'empêcher que la bague de retenue ne se déplace dans l'autre direction par rapport au tube télescopique intérieur.

Claims

37
CLAIMS
1. A lock ring assembly comprising:
an inner tubular and an outer tubular, the inner and outer tubulars being
telescopingly arranged; and
a lock ring comprising:
a profile having one or more formations formed on an outer circumference of
the
lock ring for engagement with a suitable profile formed on an inner
circumference of the
outer tubular; and
one or more teeth formed on an inner circumference of the lock ring, the teeth

being adapted to dig into an outer surface of the inner tubular member;
wherein each formation of the profile comprises a flank face and a rear face,
wherein the rear face is configured for engagement with a complementary rear
face
of the profile formed on the inner circumference of the outer tubular such
that when the
rear face is in engagement with the complementary rear face of the profile,
the teeth are
moved away from the inner tubular for ease of movement of the lock ring and
the outer
tubular relative to the inner tubular during assembly of the lock ring
assembly,
wherein the one or more teeth are configured to permit the lock ring to be
pushed
along the outer surface of the inner tubular when pushed by the outer tubular
in one
direction, and
wherein the flank face is configured for engagement with a complementary flank

face of the profile formed on the inner circumference of the outer tubular to
dig the teeth
into the outer surface of the inner tubular when the lock ring is pushed by
the outer tubular
in the other direction in order to prevent the lock ring from moving in the
other direction
relative to the inner tubular.
2. The lock ring assembly of claim 1, wherein at least the one or more
teeth of the
lock ring are formed from a harder material than the material of the inner
tubular.
3. The lock ring assembly of claim 2, wherein one or more teeth of the lock
ring are
formed from a material that is in the region of 20 Rockwell C greater than the
hardness of
the material of the inner tubular.

38
4. The lock ring assembly of claim 2 or 3, wherein the material of the lock
ring is
surface treated to provide the teeth with at least an outer surface formed
from a harder
material than the material of the inner tubular.
5. The lock ring assembly of any one of claims 1 to 4, wherein the outer
surface of the
inner tubular is relatively smooth and is provided without a ratchet mechanism
that the
teeth would otherwise have to climb and jump when moving in the said one
direction.
6. The lock ring assembly of any one of claims 1 to 5, wherein the profile
having one
or more formations formed on the outer circumference of the lock ring
comprises a thread
profile and the suitable profile formed on the inner circumference of the
outer tubular also
comprises a suitable thread profile.
7. The lock ring assembly as claimed in claim 6, wherein the flank face
defines an
acute flank angle relative to a longitudinal direction and the rear face
defines an acute cut
back angle relative to the longitudinal direction, and wherein the cut back
angle is greater
than the flank angle.
8. The lock ring assembly of claim 6, wherein the face flank defines a
flank angle in
the region of 20 degrees relative to a longitudinal direction and the rear
face defines a cut
back angle in the region of 80 degrees relative to the longitudinal direction.
9. The lock ring assembly of any one of claims 1 to 8, wherein the lock
ring further
comprises a spring member adapted to bias the lock ring in the said one
direction.
10. The lock ring assembly of claim 9, wherein the spring member acts to
push the lock
ring in the said one direction and is pre-loaded during installation to a pre-
determined
amount of loading.
11. The lock ring assembly of claim 10, wherein the pre-loading of the
spring member
ensures that there is a constant spring load exerted onto the flank angle of
the pitch profile

39
on the outer circumference of the lock ring and the flank angle on the inner
circumference
of the outer tubular.
12. The lock ring assembly of any one of claims 9 to 11, wherein the spring
member
acts between an end of the lock ring that faces in the direction of the said
other direction
and a portion of the outer tubular.
13. The lock ring assembly of any one of claims 9 to 12, wherein the lock
ring
comprises a split ring and is formed separately from the spring member.
14. The lock ring assembly of any one of claims 9 to 12, wherein the lock
ring is formed
integrally with the spring member and wherein the lock ring is provided in
circumferentially
equi-spaced tongues, each having a part circular extent.
15. The lock ring assembly of claim 14, wherein the lock ring further
comprises an
annular ring at one end comprising a screw thread formation thereon to provide
for fixing
of that end to the outer tubular.
16. The lock ring assembly of any one of claims 9 to 12, wherein the spring
member
comprises one of a wave spring, a coil spring, and one or more "S" shaped
springs.
17. A method of actuating a one way locking system comprising a lock ring
assembly
in accordance with any of claims 1 to 15, the method comprising:
pre-loading the spring member to a pre-determined amount and applying load to
the outer tubular relative to the inner tubular to move the lock ring in said
one direction;
and
relaxing the load such that the outer tubular is prevented from moving in the
other
direction relative to the inner tubular.
18. A lock ring assembly comprising:-
an inner tubular and an outer tubular, the inner and outer tubulars being
telescopingly arranged; and
a lock ring comprising:

40
a profile having one or more formations formed on an inner circumference of
the
lock ring for engagement with a suitable profile formed on an outer
circumference of the
inner tubular; and
one or more teeth formed on an outer circumference of the lock ring, the teeth

being adapted to dig into the inner surface of the outer tubular;
wherein each formation of the profile comprises a flank face and a rear face,
wherein the rear face is configured for engagement with a complementary rear
face
of the profile formed on the outer circumference of the inner tubular such
that when the
rear face is in engagement with the complementary rear face of the profile,
the teeth are
moved away from the outer tubular for ease of movement of the lock ring and
the inner
tubular relative to the outer tubular during assembly of the lock ring
assembly,
wherein the one or more teeth are configured to permit the lock ring to be
pushed
along the inner surface of the outer tubular when pushed by the inner tubular
in one
direction, and
wherein the flank face is configured for engagement with a complementary flank

face of the profile formed on the outer circumference of the inner tubular to
dig the teeth
into the inner surface of the outer tubular when the lock ring is pushed by
the inner tubular
in the other direction in order to prevent the lock ring from moving in the
other direction
relative to the outer tubular.
19. The lock ring assembly of claim 18, wherein one or more teeth of the
lock ring are
formed from a harder material than the material of the outer tubular.
20. The lock ring assembly of claim 19, wherein one or more teeth of the
lock ring are
formed from a material that is in the region of 20 Rockwell C greater than the
hardness of
the material of the outer tubular.
21. The lock ring assembly of claim 19 or 20, wherein the material of the
lock ring is
surface treated to provide the teeth with at least an outer surface formed
from a harder
material than the material of the outer tubular.
22. The lock ring assembly of any one of claims 18 to 21, wherein the
profile having
one or more formations formed on the inner circumference of the lock ring
comprises a

41
thread profile and the suitable formation profile formed on the outer
circumference of the
inner tubular also comprises a suitable thread profile.
23. The lock ring assembly as claimed in claim 22, wherein the flank face
defines an
acute flank angle relative to a longitudinal direction and the rear face
defines an acute cut
back angle relative to the longitudinal direction, and wherein the cut back
angle is greater
than the flank angle.
24. The lock ring assembly of claim 22, wherein the flank face defines a
flank angle in
the region of 20 degrees relative to a longitudinal direction and the rear
face defines a cut
back angle in the region of 80 degrees relative to the longitudinal direction.
25. The lock ring assembly of any one of claims 18 to 24, wherein the lock
ring further
comprises a spring member adapted to bias the lock ring in the said one
direction.
26. The lock ring assembly of claim 25, wherein the spring member acts to
push the
lock ring in the said one direction and is pre-loaded during installation to a
pre-determined
amount of loading.
27. The lock ring assembly of claim 26, wherein the spring member acts
between an
end of the lock ring that faces in the direction of the said other direction
and a portion of
the inner tubular.
28. The lock ring assembly of any one of claims 25 to 27, wherein the lock
ring is
formed integrally with the spring member and wherein the lock ring is provided
in
circumferentially equi-spaced tongues, each having a part circular extent.
29. A method of actuating a one way locking system comprising a lock ring
in
accordance with any one of claims 18 to 28, the method comprising:
pre-loading the spring member to a pre-determined amount and applying load to
the inner tubular relative to the outer tubular to move the lock ring in said
one direction,
and

42
relaxing the load such that the inner tubular is prevented from moving in the
other
direction relative to the outer tubular.
30. A lock ring for use as a one way movement restrictor between first and
second
telescopingly arranged tubulars to permit movement in one direction and
prevent
movement in the other direction of one of the first and second tubulars
relative to the other
of the first and second tubulars, the lock ring comprising:
a lock ring section having:
a profile having one or more formations formed on one of an outer or inner
circumference of the lock ring; and
one or more teeth formed on the other of the outer or inner circumference of
the lock ring;
an annular section; and
a spring section located axially between the lock ring section and the annular

section,
wherein the lock ring defines a plurality of circumferentially equi-spaced
tongues,
each tongue extending from the annular section and each tongue defining a
portion of the
lock ring section and a portion of the spring section; and
wherein each tongue defines an "S" shaped spring.
31. The lock ring of claim 30, wherein each formation of the profile is
formed on the
outer circumference of the lock ring and each of the one or more teeth are
formed on the
inner circumference of the lock ring.
32. The lock ring of claim 30 or 31, wherein each tongue has a part
circular extent.
33. The lock ring of any one of claims 30 to 32, wherein the annular
section comprises
a screw thread formation thereon for fixing the lock ring to one of the first
and second
tubulars.
34. The lock ring of any one of claim 30 to 33, wherein the lock ring
section and the
spring section are axially non-overlapping.

43
35. The lock ring of any one of claim 30 to 34, wherein the lock ring is
unitary.
36. The lock ring of any one of claim 30 to 35, wherein each formation of
the profile
comprises a flank face defining an acute flank angle relative to a
longitudinal direction and
a rear face which defines an acute cut back angle relative to the longitudinal
direction.
37. The lock ring of claim 36, wherein each flank face defines a flank
angle in the
region of 20 degrees relative to the longitudinal direction and each rear face
defines a cut
back angle in the region of 80 degrees relative to the longitudinal direction.
38. A lock ring assembly, comprising:
a first tubular and a second tubular, the first and second tubulars being
telescopingly arranged; and
the lock ring of claim 36 or 37,
wherein the rear face of each formation of the profile of the lock ring is
configured
for engagement with a complementary profile formed on the surface of the first
tubular in
order to move the teeth of the lock ring away from a surface of the second
tubular for ease
of movement of the lock ring and the first tubular relative to the second
tubular during
assembly of the lock ring assembly, and
wherein each flank face of each formation of the profile of the lock ring is
configured for engagement with the complementary profile formed on the surface
of the
first tubular and/or the said one or more teeth of the lock ring are
configured so as to
permit the lock ring to be pushed along the surface of the second tubular when
pushed by
the first tubular in one direction and to cause the teeth to dig into the
surface of the second
tubular when the push in said one direction is removed or when it is pushed by
the first
tubular in the other direction in order to prevent the lock ring from moving
in the other
direction relative to the second tubular when the lock ring assembly is in
use.
39. The lock ring assembly of claim 38, wherein the first tubular is an
outer tubular, the
second tubular is an inner tubular, the one or more formations of the profile
of the lock ring
are formed on the outer circumference of the lock ring for engagement with a
complementary profile formed on an inner surface of the outer tubular, and the
one or

44
more teeth of the lock ring are formed on the inner circumference of the lock
ring, the teeth
being adapted to dig into an outer surface of the inner tubular.
40. The lock ring assembly of claim 38 or 39, wherein the spring section
acts to push
the lock ring in the said one direction and is pre-loaded during installation
to a pre-
determined amount of loading.
41. The lock ring assembly of claim 40, wherein the pre-loading of the
spring section
ensures that there is a constant spring load exerted onto the flank face of
each profile of
the lock ring and a corresponding flank face of the complementary profile
formed on the
surface of the first tubular.
42. The lock ring assembly of any one of claims 38 to 41, wherein the
spring section
acts between an end of the lock ring that faces in the direction of the said
other direction
and a portion of the first tubular.
43. A lock ring for use as a one way movement restrictor between first and
second
telescopingly arranged tubulars to permit movement in one direction and
prevent
movement in the other direction of one of the first and second tubulars
relative to the other
of the first and second tubulars, the lock ring comprising:
a lock ring section having:
a profile having one or more formations formed on one of an outer or an
inner circumference of the lock ring; and
one or more teeth formed on the other of the outer or inner circumference of
the lock ring;
wherein each formation of the profile comprises a flank face defining an
acute flank angle relative to a longitudinal direction and a rear face which
defines an acute
cut back angle relative to the longitudinal direction
an annular section; and
a spring section located axially between the lock ring section and the annular

section,
wherein the spring section is configured to urge the lock ring section and the

annular section axially apart when the spring section is subjected to axial
compression and

45
the spring section is configured to urge the lock ring section and the annular
section axially
together when the spring section is subjected to axial tension.
44. The lock ring of claim 43, wherein each formation of the profile is
formed on the
outer circumference of the lock ring and each of the one or more teeth are
formed on the
inner circumference of the lock ring.
45. The lock ring of claim 43 or 44, wherein each flank face defines a
flank angle in the
region of 20 degrees relative to the longitudinal direction and each rear face
defines a cut
back angle in the region of 80 degrees relative to the longitudinal direction.
46. The lock ring of any one of claims 43 to 45, wherein the lock ring
defines a plurality
of circumferentially equi-spaced tongues, each tongue extending from the
annular section
and each tongue defining a portion of the lock ring section and a portion of
the spring
section.
47. The lock ring of claim 46, wherein each tongue has a part circular
extent.
48. The lock ring of any one of claims 46 to 47, wherein the annular
section comprises
a screw thread formation thereon for fixing the lock ring to one of the first
and second
tubulars.
49. The lock ring of any one of claims 46 to 48, wherein each tongue
defines an "S"
shaped spring.
50. The lock ring of any one of claims 46 to 49, wherein the lock ring
section and the
spring section are axially non-overlapping.
51. The lock ring of any one of claims 43 to 50, wherein the lock ring is
unitary.
52. A lock ring assembly, comprising:
a first tubular and a second tubular, the first and second tubulars being
telescopingly arranged; and

46
the lock ring as claimed of any one of claims 43 to 51,
wherein the rear face of each formation of the profile of the lock ring is
configured
for engagement with a complementary profile formed on the surface of the first
tubular in
order to move the teeth of the lock ring away from a surface of the second
tubular for ease
of movement of the lock ring and the first tubular relative to the second
tubular during
assembly of the lock ring assembly, and
wherein each flank face of each formation of the profile of the lock ring is
configured for engagement with the complementary profile formed on the surface
of the
first tubular and/or the said one or more teeth of the lock ring are
configured so as to
permit the lock ring to be pushed along the surface of the second tubular when
pushed by
the first tubular in one direction and to cause the teeth to dig into the
surface of the second
tubular when the push in said one direction is removed or when it is pushed by
the first
tubular in the other direction in order to prevent the lock ring from moving
in the other
direction relative to the second tubular when the lock ring assembly is in
use.
53. The lock ring assembly of claim 52, wherein the first tubular is an
outer tubular, the
second tubular is an inner tubular, the one or more formations of the profile
of the lock ring
are formed on the outer circumference of the lock ring for engagement with a
complementary profile formed on an inner surface of the outer tubular, and the
one or
more teeth of the lock ring are formed on the inner circumference of the lock
ring, the teeth
being adapted to dig into an outer surface of the inner tubular.
54. A lock ring assembly, comprising:
a first tubular and a second tubular, the first and second tubulars being
telescopingly arranged; and
the lock ring as claimed in any one of claims 46 to 50,
wherein the rear face of each formation of the profile of the lock ring is
configured
for engagement with a complementary profile formed on the surface of the first
tubular in
order to move the teeth of the lock ring away from a surface of the second
tubular for ease
of movement of the lock ring and the first tubular relative to the second
tubular during
assembly of the lock ring assembly, and
wherein each flank face of each formation of the profile of the lock ring is
configured for engagement with the complementary profile formed on the surface
of the

47
first tubular and/or the said one or more teeth of the lock ring are
configured so as to
permit the lock ring to be pushed along the surface of the second tubular when
pushed by
the first tubular in one direction and to cause the teeth to dig into the
surface of the second
tubular when the push in said one direction is removed or when it is pushed by
the first
tubular in the other direction in order to prevent the lock ring from moving
in the other
direction relative to the second tubular when the lock ring assembly is in
use.
55. The lock ring assembly of claim 54, wherein the first tubular is an
outer tubular, the
second tubular is an inner tubular, the one or more formations of the profile
of the lock ring
are formed on the outer circumference of the lock ring for engagement with a
complementary profile formed on an inner surface of the outer tubular, and the
one or
more teeth of the lock ring are formed on the inner circumference of the lock
ring, the teeth
being adapted to dig into an outer surface of the inner tubular.
56. The lock ring assembly of claim 54 or 55, wherein the spring section
acts to push
the lock ring in the said one direction and is pre-loaded during installation
to a pre-
determined amount of loading.
57. The lock ring assembly of claim 56, wherein the pre-loading of the
spring section
ensures that there is a constant spring load exerted onto the flank face of
each profile of
the lock ring and a corresponding flank face of the complementary profile
formed on the
surface of the first tubular.
58. The lock ring assembly of any one of claims 54 to 57, wherein the
spring section
acts between an end of the lock ring that faces in the direction of the said
other direction
and a portion of the first tubular.

Description

CA 02748672 2015-09-10
LOCK RING APPARATUS AND METHOD
The present invention relates to an apparatus and method, and particularly
relates to downhole tools used in oil and gas wellbores.
Conventionally, many different types of tools are used when drilling for oil
and gas
and, conventionally, such tools are connected together into a string of
tubulars
and run into the wellbore. There are several different stages when creating a
wellbore ready to produce oil and gas such as drilling, casing, cementing and
completing the wellbore. Each stage requires a different set of tools and
processes.
For example, completing the wellbore normally occurs toward the end of the
process of creating an oil and gas production well. In many such wells there
is a
requirement for example to prevent sand being produced along with the oil or
gas
from the production zone and this is normally achieved by using sand screens
which are placed in the production zone of the wellbore and act very much like

sieves, in that they allow the oil or gas to pass through their side walls but
prevent
the sand from passing through their side walls by utilising a mesh which is
sufficiently sized such that its apertures are smaller than the grains of
sand. It is
important however to anchor the sand screens in the wellbore and this is
conventionally achieved by using a mechanically set or hydraulically set slips

anchor or a hanger which can be actuated to move a set of anchoring slips
outwards to grip into or bite into the open hole formation and thus can be
used to
transfer load from the anchor and any other tools connected to the anchor such
as sand screens, etc. into the formation. Conventionally, a mechanically set
slip
anchor comprises a set of slips that sit in a wedge shaped recess and which,
when pushed axially, will be also forced radially outwardly. However, such
conventionally mechanical slips suffer from

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
2
disadvantage that they are somewhat limited to the extent that they can
extend radially outwardly.
Accordingly, it is an object of a first aspect of the present invention to
provide embodiments of a slip mechanism that provides the possibility of a
greater radial expansion or a higher expansion slip system than available
with conventional tools.
From another and more important aspect, it is well known in the oil and
gas completion field and in many other oil and non-oil fields to use lock
rings that operate on a ratchet mechanism principle to provide a one way
locking mechanism such that an outer telescopic tubular and the lock ring
can be moved one way along a ratchet mechanism (formed upon the outer
circumference of an inner tubular telescopingly arranged within the outer
tubular) upon actuation of mechanical or hydraulic operation in order to
actuate e.g. a slips system or a packer but the one way lock ring ratchet
mechanism prevents the outer tubular and the lock ring from moving back
in the opposite direction. Similarly, the one way locking mechanism can
be configured such that an inner telescoping tubular and the lock ring can
be moved one way along a ratchet mechanism (formed upon the inner
circumference of an outer tubular telescopingly arranged outwith the inner
tubular). Thus, the one way lock ring ratchet mechanism prevents e.g.
deflation of the packer or prevents a slips system from moving radially
inward. However, such conventional lock ring ratchet mechanisms suffer
from the disadvantage that they have a reasonably high backlash distance
because of the reasonably high pitch of the lock ring ratchet mechanism
profile. In other words, the lock ring has to be moved the relatively long
distance of the length of each tooth until each tooth clears the next
respective tooth of the ratchet upon which the lock ring sits around before
the lock ring is prevented from moving back. Therefore, if the lock ring

CA 02748672 2011-06-30
WO 2010/084353 PCT/GB2010/050093
3
does not clear the tooth before the pressure of the mechanical actuation
mechanism is removed then the lock ring will relax back to the last point it
cleared. There are also a number of failure modes with conventional lock
rings including the ratchet mechanism teeth shearing or the supporting
tubular failing due to burst or collapse. Conventional ways to prevent such
burst or collapse can include increasing the length of the lock ring because
doing so spreads the load but sometimes this cannot be achieved due to
space limitations. Furthermore, conventional lock rings have back lash in
two areas:-
1) on the static ratchet mechanism profile there is axial slop
because the lock ring must be allowed to expand; and
2) on the moveable ratchet mechanism profile because it has to
jump a thread form as it moves along axially, as discussed above.
Typically, a conventional body lock ring will comprise a 16 Thread Per Inch
(TPI) moveable ratchet mechanism profile and an 8 TPI static thread
profile. It is also known to try and reduce back lash by increasing the pitch
on the moveable ratchet mechanism profile but the lock ring then becomes
difficult to manufacture and also the lock ring then becomes very prone to
failure due to any debris getting between it and the static tubular member
and thus becomes less reliable. It should also be noted that should the
lock ring fail then the user will experience catastrophic failure of the tool.

Conventional lock rings are typically formed of 4140 (18-22 Rockwell C
hardness) steel which is typically the same as the mandrel or tubular
about which the lock ring is placed.
Accordingly, it is an object of another aspect of the present invention to
provide a reduced backlash lock ring ratchet mechanism that can be used
on a wide variety of tools whether downhole or otherwise.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
4
From a yet further aspect, there is a problem with conventional mechanical
actuation mechanisms for e.g. slips or packers in that they can be
unintentionally/accidentally set whilst running in the hole.
Accordingly, it is an object of another aspect of the present invention to
overcome such problems with conventional mechanical actuation
mechanisms for e.g. any tools that require to be actuated downhole by
mechanical means by providing a setting section that is locked until
actuation is desired and the setting section is positively actuated.
According to a first aspect of the present invention there is provided a lock
ring for use as a one way movement restrictor between two telescopingly
arranged tubulars to permit movement in one direction and prevent
movement in the other direction of one tubular relative to the other tubular;
the lock ring comprising:-
a profile having one or more formations formed on the outer
circumference for engagement with a suitable formation profile formed on
the inner circumference of the outer telescopic tubular; and
one or more teeth formed on its inner circumference, the teeth
being adapted to dig into the outer surface of the inner telescopic member;
such that the profile having one or more formations on the outer
circumference and/or the said one or more teeth permits the lock ring to
be pushed along the outer surface of the inner telescopic tubular when
pushed by the outer telescopic tubular in one direction; and
is further adapted to dig the teeth into the outer surface of the inner
telescopic tubular when the push in said one direction is removed or when
it is pushed by the outer telescopic tubular in the other direction in order
to
prevent the lock ring from moving in the other direction relative to the inner

telescopic tubular.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
Preferably, at least the one or more teeth of the lock ring are formed from
a harder material than the material of the inner telescopic member and
typically, the at least the one or more teeth of the lock ring are formed from

a material that is in the region of 20 Rockwell C greater than the hardness
5 of the material of the inner telescopic tubular. Alternatively or in
addition,
the material of the lock ring may be surface treated to provide the teeth
with at least an outer surface formed from a harder material than the
material of the inner telescopic member.
Typically, the lock ring is hardness treated during manufacture.
Typically, the outer surface of the inner telescopic tubular is relatively
smooth and is preferably provided without a ratchet mechanism that the
teeth would otherwise have to climb and jump when moving in the said
one direction.
Preferably, the profile having one or more formations formed on the outer
circumference of the lock ring comprises a thread profile and the suitable
formation profile formed on the inner circumference of the outer telescopic
tubular also comprises a suitable thread profile.
Preferably, the thread profile of the outer circumference of the lock ring
comprises a flank angle in the region of 20 degrees and a cut back rear
face angle in the region of 80 degrees radially outwardly in the other
direction from the longitudinal axis of the lock ring.
Preferably, the lock ring further comprises a spring member adapted to
bias the lock ring in the said one direction. The spring member preferably
acts to push the lock ring in the said one direction and is preferably pre-
loaded during installation to a pre-determined amount of loading.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
6
Preferably, the pre-loading of the spring member ensures that there is a
constant spring load exerted onto the flank angle of the pitch profile on the
outer circumference of the lock ring and the flank angle on the inner
circumference of the outer telescopic tubular. Preferably, the thread
profile of the outer circumference of the lock ring comprises a flank angle
in the region of 20 degrees and a cut back rear face angle in the region of
80 degrees radially outwardly in the other direction from the longitudinal
axis of the lock ring.
Typically, the spring member acts between an end of the lock ring that
faces in the direction of the said other direction and a portion of the outer
telescopic tubular.
In one embodiment the lock ring may be a split ring or "C" shaped lock ring
and in such an embodiment, the lock ring is formed separately from the
spring member.
In a preferred embodiment, the lock ring is formed integrally with the
spring member and in such an embodiment, the lock ring is preferably
castellated and/or is provided in circumferentially equi-spaced tongues,
each having a part circular extent. The lock ring may further comprise an
annular ring at one end comprising a screw thread formation thereon to
provide for fixing of that end to the outer telescopic tubular and in such an
embodiment, the spring member is typically located in between the lock
ring section and the annular ring, with the lock ring, the spring member
and the annular ring all being integrally formed in a one piece unit.
Preferably, the inner diameter of the lock ring teeth is preferably slightly
less than the outer diameter of the inner telescopic tubular.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
7
The spring member may be a wave spring, a coil spring, one or more "S"
shaped springs, or any other suitable spring.
According to the present invention there is also provided a method of
actuating a one way locking system comprising a lock ring in accordance
with the first aspect of the present invention, the method comprising pre-
loading the spring member to a pre-determined amount and applying load
to the outer telescopic member relative to the inner telescopic member to
move the lock ring in said one direction and relaxing the load such that the
outer telescopic tubular is prevented from moving in the other direction
relative to the inner telescopic member.
According to a second aspect of the present invention there is provided a
lock ring for use as a one way movement restrictor between two
telescopingly arranged tubulars to permit movement in one direction and
prevent movement in the other direction of one tubular relative to the other
tubular; the lock ring comprising:-
a profile having one or more formations formed on the inner
circumference for engagement with a suitable formation profile formed on
the outer circumference of the inner telescopic tubular; and
one or more teeth formed on its outer circumference, the teeth
being adapted to dig into the inner surface of the outer telescopic member;
such that the profile having one or more formations on the inner
circumference and/or the said one or more teeth permits the lock ring to
be pushed along the inner surface of the outer telescopic tubular when
pushed by the inner telescopic tubular in one direction; and
is further adapted to dig the teeth into the inner surface of the outer
telescopic tubular when the push in said one direction is removed or when
it is pushed by the inner telescopic tubular in the other direction in order
to

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
8
prevent the lock ring from moving in the other direction relative to the outer

telescopic tubular.
Preferably, at least the one or more teeth of the lock ring are formed from
a harder material than the material of the outer telescopic member and
typically, the at least one or more teeth of the lock ring are formed from a
material that is in the region of 20 Rockwell C greater than the hardness of
the material of the outer telescopic tubular. Alternatively or in addition,
the
material of the lock ring may be surface treated to provide the teeth with at
least an outer surface formed from a harder material than the material of
the outer telescopic member.
Typically, the lock ring is hardness treated during manufacture.
Typically, the inner surface of the outer telescopic tubular is relatively
smooth and is preferably provided without a ratchet mechanism that the
teeth would otherwise have to climb and jump when moving in the said
one direction.
Preferably, the profile having one or more formations formed on the inner
circumference of the lock ring comprises a thread profile and the suitable
formation profile formed on the outer circumference of the inner telescopic
tubular also comprises a suitable thread profile.
Preferably, the thread profile of the inner circumference of the lock ring
comprises a flank angle in the region of 20 degrees and a cut back rear
face angle in the region of 80 degrees radially outwardly in the other
direction from the longitudinal axis of the lock ring.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
9
Preferably, the lock ring further comprises a spring member adapted to
bias the lock ring in the said one direction. The spring member preferably
acts to push the lock ring in the said one direction and is preferably pre-
loaded during installation to a pre-determined amount of loading.
Preferably, the pre-loading of the spring member ensures that there is a
constant spring load exerted onto the flank angle of the pitch profile on the
inner circumference of the lock ring and the flank angle on the outer
circumference of the inner telescopic tubular. Preferably, the thread
profile of the inner circumference of the lock ring comprises a flank angle
in the region of 20 degrees and a cut back rear face angle in the region of
80 degrees radially outwardly in the other direction from the longitudinal
axis of the lock ring.
Typically, the spring member acts between an end of the lock ring that
faces in the direction of the said other direction and a portion of the outer
telescopic tubular.
In one embodiment the lock ring may be a split ring or "C" shaped lock ring
and in such an embodiment, the lock ring is formed separately from the
spring member.
In a preferred embodiment, the lock ring is formed integrally with the
spring member and in such an embodiment, the lock ring is preferably
castellated and/or is provided in circumferentially equi-spaced tongues,
each having a part circular extent. The lock ring may further comprise an
annular ring at one end comprising a screw thread formation thereon to
provide for fixing of that end to the inner telescopic tubular and in such an
embodiment, the spring member is typically located in between the lock
ring section and the annular ring, with the lock ring, the spring member
and the annular ring all being integrally formed in a one piece unit.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
Preferably, the outer diameter of the lock ring teeth is slightly greater than

the inner diameter of the outer telescopic tubular.
5 The spring member may be a wave spring, a coil spring, one or more "S"
shaped springs, or any other suitable spring.
According to the present invention there is also provided a method of
actuating a one way locking system comprising a lock ring in accordance
10 with the second aspect of the present invention, the method comprising
pre-loading the spring member to a pre-determined amount and applying
load to the inner telescopic member relative to the outer telescopic
member to move the lock ring in said one direction and relaxing the load
such that the inner telescopic tubular is prevented from moving in the
other direction relative to the outer telescopic member.
According to a third aspect of the present invention there is provided an
expandable slips system for use on a mandrel having a longitudinal axis,
the mandrel adapted to be run into a borehole, the expandable slips
system comprising:-
at least one slip which in use is adapted to be moved outwardly
from the longitudinal axis of the mandrel to grip against and thereby
engage a downhole formation, the at least one slip comprising at least one
angled member;
at least one cone member for engagement with the at least one
slip, the cone member comprising at least one angled member for
engagement with the at least one angled member of the slip; and
at least one cone member expansion device for engagement with
the at least one cone member, the cone member expansion device

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
11
comprising at least one angled member for engagement with another at
least one angled member of the cone member.
According to the third aspect of the present invention there is provided a
method of actuating an expandable slips system in accordance with the
apparatus of the first aspect of the present invention, comprising:-
moving the cone member expansion device in a direction parallel
with the longitudinal axis of the mandrel such that the cone member is
moved radially outwardly and the slip is moved radially outwardly from a
running in lying flat configuration to an extended in use configuration.
Typically, the slip system is arranged such that movement of the at least
one cone member expansion device in a direction parallel to the
longitudinal axis of the mandrel causes the cone member to move:-
in a direction parallel to the longitudinal axis of the mandrel; and
in a radially outwards direction perpendicular to the longitudinal axis
of the mandrel.
Typically, the slip system is further arranged such that the said movement
of the at least one cone member causes the slip to move in a radially
outwards direction perpendicular to the longitudinal axis of the mandrel.
Preferably, there are two cone member expansion devices spaced apart
along the longitudinal axis of the mandrel, where one cone member
expansion device may be fixed to the mandrel and the other cone member
expansion device may be moveable along the longitudinal axis of the
mandrel with respect to the said one cone member expansion device such
that the moveable cone member expansion device can be selectively
moved toward and away from the said one fixed cone member expansion
device.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
12
Preferably, there are two cone members spaced apart along the
longitudinal axis of the mandrel, where one cone member may be
engaged with the fixed cone member expansion device and the other cone
member may be engaged with the moveable cone member expansion
device such that the said one cone member can be selectively moved
toward and away from the said other cone member when the moveable
cone member expansion device is selectively moved toward and away
from the said one fixed cone member expansion device to respectively
move the slip radially outwardly and inwardly with respect to the mandrel.
Typically, the pair of cone members are telescopingly coupled to one
another such that they are prevented from relative movement with respect
to one another other than longitudinal movement.
Typically, longitudinal movement of the moveable cone member
expansion device toward the said one fixed cone member expansion
device causes longitudinal movement of one cone member toward the
other cone member and also radially outwards movement of both cone
members which in turn causes radially outwards movement of the slip
such that the slip moves from a running in lying flat configuration to an
extended in use configuration.
Furthermore, longitudinal movement of the moveable cone member
expansion device away from the said one fixed cone member expansion
device causes longitudinal movement of one cone member away from the
other cone member and also radially inwards movement of both cone
members which in turn causes radially inwards movement of the slip such
that the slip returns to the running in lying flat configuration from the
radially extended in use configuration.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
13
Typically, the expandable slips system comprises one slip.
One or more expandable slips systems are preferably provided on one
mandrel and in a preferred embodiment, three expandable slips systems
are provided on one mandrel, where the three expandable slips systems
are preferably provided equi-spaced 120 degrees around the
circumference of the mandrel.
Preferably, the or each angled member of the slip comprises a surface
provided at an angle between the longitudinal and the perpendicular with
respect to the mandrel and preferably, the or each angled member of the
respective cone member also comprises a similarly angled surface that
engages with and co-operates with the angled surface of the slip.
Preferably, the or each angled member of the or each cone member
expansion device comprises a surface provided at an angle between the
longitudinal and the perpendicular with respect to the mandrel and
preferably, the or each another angled member of the or each cone
member also comprises a similarly angled surface that engages with and
co-operates with the angled surface of the cone member expansion
device.
Typically, the or each angled member/angled surface comprises either an
angled key or an angled slot within which the key moveably resides and is
retained. Preferably, the angled surface of the slip comprises one of a key
or a slot and the similarly angled surface of the respective cone member
comprises the other of the key or the slot, wherein the angled surface
angles from radially innermost to radially outermost away from the
longitudinal centre of the slip. Preferably, the angled surface of the cone

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
14
member expansion device comprises one of a key or a slot and the
similarly angled surface of the respective cone member comprises the
other of the key or the slot, wherein the angled surface angles from
radially innermost to radially outermost away from the longitudinal centre
of the respective cone member.
Typically, the downhole formation can comprise a natural formation such
as the sidewall of a section of open hole borehole or a manmade
formation such as a downhole cemented section or a section of installed
downhole tubular such as casing or liner.
Typically, the mandrel is adapted to be included in a string of downhole
tubulars and preferably has suitable connections such as screw threaded
connections to enable such inclusion.
According to a fourth aspect of the present invention there is provided an
interlock and setting section for a downhole tool system, the interlock and
setting section comprising:-
a shifting profile located within a throughbore of the downhole tool
system, wherein the shifting profile is capable of being coupled to by a
shifting tool in the throughbore of the downhole tool system, in order to
move the shifting profile with respect to the downhole tool system;
a load connector member coupled to the shifting profile and further
coupled to a load setting member arranged to deliver a load to a tool as
required;
wherein there is further provided a selective locking mechanism to
selectively lock at least the load setting member to at least one of the
downhole tool system and the shifting profile.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
Preferably, the downhole tool system comprises a static mandrel against
which a load is to be generated, wherein the static mandrel may be rigidly
connected back to the surface of the downhole well.
5 Typically, the selective locking mechanism may be unlocked by movement
of the shifting profile with respect to the static mandrel such that the lock
acting between the load setting member and the at least one of the
downhole tool system and the shifting profile is removed.
10 Typically, the locking mechanism selectively locks the load setting
member
to the static mandrel.
Preferably, the selective locking mechanism comprises a two lock
members located in a recess in the static mandrel and which, in a locking
15 configuration, are arranged such that one of the lock members is
restrained from longitudinal movement with respect to the static mandrel
and wherein the lock members radially support one another to permit load
to be transferred from the load setting member to the static member and
preferably to the shifting profile.
Preferably, the other of the lock members can be moved longitudinally with
respect to the static mandrel by a pre-determined length, when in the
locking configuration, such that the radial support between the two lock
members is removed and the locking mechanism is unlocked. Preferably,
the locking members comprise one or more radially projecting and co-
operating formations in the locking configuration which are adapted to no
longer co-operate when the said other locking member is moved relative
to the said one locking member.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
16
Typically, at least one of the couplings between the load connecting
member and i) the shifting profile and ii) the load setting member allows
the shifting tool to move by a slightly greater distance than the said pre-
determined length before the coupling therebetween is capable of
transferring load from the shifting profile to the load setting member.
Preferably, the shifting profile is initially secured to the static mandrel by

disruptable device to prevent any unwanted movement therebetween prior
to the selective unlocking occurring and more preferably, the disruptable
device comprises a shear screw or shear pin or the like.
There is also provided a method of operating an interlock and setting
section in accordance with the fourth aspect of the present invention from
an initial locking configuration to an unlocked and load setting
configuration, the method comprising
running a shifting tool into the throughbore of the downhole tool
system;
engaging the shifting tool with the shifting profile;
pulling or pushing the shifting tool to destroy or otherwise disable
the disruptable device;
further pushing or pulling the shifting tool to move the shifting profile
the pre-determined length such that the radial support between the two
lock members is removed and the locking mechanism is unlocked; and
further pushing or pulling the shifting tool to move the shifting profile
thereby transferring load into the setting sleeve with respect to the static
mandrel.
Typically, the load setting member is coupled to a tool that requires a load
to be applied to it to actuate said tool.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
17
Preferably, the load setting member is located on the outside of the
down hole tool system.
Embodiments of the present invention will now be described by way of
example only, with reference to the accompanying drawings, in which:-
Fig. 1 is a part cross-sectional side view of the first of five portions
of a mechanical set slips anchor in accordance with the first,
second and third aspects of the present invention and is shown in a
running-in hole or prior-to-actuation configuration, where the portion
shown in Fig. lA is the upper most in use end of the mechanical set
slips anchor;
Fig. 1B is a part cross-sectional side view of a second portion of the
mechanical set slips anchor of Fig. 1A, where the portion shown in
Fig. 1B in use is immediately below the portion shown in Fig. lA
and immediately above the portion shown in Fig. 1C;
Fig. 1C is a part cross-sectional side view of a third portion of the
mechanical sets slips anchor of Fig. lA and which in use is
immediately below the portion shown in Fig. 1B and immediately
above the portion shown in Fig. 1E;
Fig. 1D is a close up and more detailed cross-sectional view of one
part of the third portion of the mechanical sets slips anchor of Fig.
1C, where the part shown in Fig. 1D is an embodiment of a reduced
back lash lock ring in accordance with the third aspect of the
present invention;
Fig. 1DA is an even more close up and even more detailed cross-
sectional view of the lock ring shown in Fig. 1D;
Fig. 1DB is a relatively close up and detailed cross-sectional view of
an alternative and preferred embodiment of a reduced back lash
lock ring in accordance with the third aspect of the present invention
which can be used instead of the lock ring shown in Fig. 1DA;

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
18
Fig. lE is a part cross-sectional side view of a fourth portion of the
mechanical sets slips anchor of Fig. lA and which in use is
immediately below the portion shown in Fig. 1C and immediately
above the portion shown in Fig. 1H;
Fig. 1F is a close up and more detailed cross-sectional side view of
a part of the fourth portion of the mechanical set slips anchor of Fig.
lE and shows an interlock which forms a part of the interlock
mechanism embodiment in accordance with the second aspect of
the present invention;
Fig. 10 is a closer up and more detailed cross-sectional side view
of a setting key which forms a part of the interlock mechanism
embodiment in accordance with the second aspect of the present
invention;
Fig. 1H is a part cross-sectional side view of a fifth portion of the
mechanical set slips anchor of Fig. lA and which in use is located
immediately below the portion shown in Fig. lE and forms the lower
most portion of the mechanical set slips anchor in use;
Fig. 2A is a cross-sectional side view of the mechanical set slips
anchor of Figs. lA to 1H but shown in a post actuation or set
configuration where the portion shown in Fig. 2A is the upper most
in use end of the mechanical set slips anchor;
Fig. 2B is a cross-sectional side view of a second portion of the
mechanical set slips anchor of Fig. 2A, where the portion shown in
Fig. 2B in use is located immediately below the portion shown in
Fig. 2A and immediately above the portion shown in Fig. 2C, and
more particularly shows the slips having been actuated radially
outwardly.
Fig. 2C is a cross-sectional side view of a third portion of the
mechanical set slips anchor of Fig. 2A and which in use is located
immediately below the portion shown in Fig. 2B and immediately

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
19
above the portion shown Fig. 2D, and more particularly shows an
embodiment of a lock ring in accordance with the third aspect of the
present invention;
Fig. 2D is a cross-sectional side view of a fourth portion of the
mechanical set slips anchor of Fig. 2A and which in use is located
immediately below the portion shown in Fig. 2C and immediately
above the portion shown in Fig. 2E, and more particularly shows an
embodiment of an interlock mechanism in accordance with the
second aspect of the present invention;
Fig. 2E is a cross-sectional side view of a fifth portion of the
mechanical set slips anchor of Fig. 2A and which in use is located
immediately below the portion shown in Fig. 2D, and which forms
the lower most portion in use of the mechanical set slips anchor;
Fig. 3A is a perspective side view (with a portion cut away from the
slip section for clarity) of the mechanical set slips anchor of Figs. 2A
to 2E in the post-actuation or set configuration;
Fig. 3B is a more detailed view of the actuated slips of Fig. 3A;
Fig. 4 is a cross-sectional end view of the slip section taken through
section 1-1 on Fig. 2B;
Fig. 5A is a part cross-sectional perspective view of some of the
components of the mechanical set slips anchor that form the
interlock mechanism in accordance with the second aspect of the
present invention;
Fig. 5B is a more detailed view of the setting keys of Fig. 5A;
Fig. 5C is a more detailed view of the gap between the teeth of the
setting keys of Fig. 5B;
Fig. 5D is a more detailed view of the interlock keys of Fig. 5A;
Fig. 6A is a perspective side view of the reduced backlash lock ring
of Fig. 1D and Fig. 1DA;
Fig. 6B is an end view of the reduced backlash lock ring of Fig. 6A;

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
Fig. 6C is a cross-sectional side view across section AA of Fig. 6B
of the reduced backlash lock ring;
Fig. 6D is a perspective side view of the reduced backlash lock ring
of Fig. 6A with a quarter circle of a portion of the lock ring removed
5 for clarity and comparison purposes;
Fig. 6E is a side view of the lock ring of Fig. 6D with the quarter
circle portion removed to aid comparison purposes between the
outer and inner ratchet mechanisms;
Fig. 7A is an exploded perspective view of the slips mechanism of
10 Fig. 3B;
Fig. 7B is a perspective view of a cone of the slips mechanism of
Fig. 7A;
Fig. 7C is another perspective view taken from a different angle of
the cone of Fig. 7B;
15 Fig. 8A is a perspective side view of the preferred reduced backlash
lock ring of Fig. 1DB;
Fig. 8B is an end view of the preferred reduced backlash lock ring
of Fig. 8A;
Fig. 8C is a cross-sectional side view across section D-D of Fig. 8B
20 of the preferred embodiment of reduced backlash lock ring;
Fig. 8D is a cross-sectional side view across section E-E of Fig. 8B
of the preferred embodiment of reduced backlash lock ring; and
Fig. 8E is a detailed view of the section highlighted G of one tongue
of the preferred reduced backlash lock ring of Fig. 8D.
The mechanical set slips anchor 100 shown in the Figures can be
regarded as having three distinct sections, these being:-
a) slips section 40 (shown mainly in Fig. 1B in the unset or
running in configuration and in Fig. 2B in the set or post-actuation
configuration) in accordance with the first aspect of the present invention;

CA 02748672 2011-06-30
WO 2010/084353 PCT/GB2010/050093
21
b) locking section 50 (which can be best seen in Fig. 1C in the
unset or running in configuration and in Fig. 2C in the set or post-actuation
configuration) in accordance with the second aspect of the present
invention; and
c) setting section 60 (which can be best seen in Fig. 1 E in the
running in or pre-actuation configuration and Fig. 2D in the post-actuation
or set configuration) in accordance with the third aspect of the present
invention.
However, it should be clearly noted that the slips section 40 could be used
with other locking sections 50 or with other setting sections 60; for
instance, the slips section 40 could be hydraulically set rather than
mechanically set and in such a situation would the tool would be provided
with a hydraulical actuation mechanism instead of the mechanical setting
section 60. Furthermore, it should be noted that the locking section 50
and/or setting section 60 could be used in different applications and tools
such as with e.g. packer tools used to create a pressure barrier in the
annulus in a wellbore, etc..
The three main sections of the tool will now be described in turn.
Slips Section 40
Slips section 40 comprises a top sub 21 which has a suitable connection
such as a pin or box screw threaded connection provided at its very upper
most end (left hand end as shown in Fig. 1A and 2A) for connection to a
suitable connection provided at the lower most end of a down hole string
into which the mechanical set slips anchor 100 is to be included. The
lower end of the top sub 21 is securely screw threaded to the upper end of
a cone mandrel 23. The cone mandrel 23 is provided with an upper cone

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
22
expander 20 which is securely screw threaded at the upper end of the
cone mandrel 23 and this can be best seen in Fig. 2A. Thus, in normal
operation, the upper cone expander 20 is securely fixed to the cone
mandrel 23. A lower cone expander 17 is located about the mid to lower
half of the cone mandrel 23 and a number of cones 18 and slips 19 are
located between the upper cone expander 20 and lower cone expander 17
and, in general, movement of the lower cone expander 17 toward the
upper cone expander 20 in a direction along the longitudinal axis of the
cone mandrel 23 results in radially outward movement of the cones 18 and
subsequently the slips 19.
Operation and expansion of the slips 19 will now be described in more
detail.
As can be best seen in Fig. 4, there are three slips 19 equi-spaced 120
apart around the circumference of the cone mandrel 23 and, as best seen
in Figs. 3B and Fig. 7A, each slip 19 comprises a pair of outwardly
projecting arms 25U, 25L. Each of the arms 25U, 25L are arranged at an
angle such that they are angled from radially inner most to radially outer
most away from the centre of the slip 19. The slips 19 are mounted in a
cone 18U, 18L at each end where the arms 25U, 25L sit in respective
angled recesses 27U, 27L formed in the cones 18U, 18L. The angled
recesses 27U, 27L are again angled from radially inner most to radially
outer most in a direction away from the centre of the two cones 18U, 18L
as shown in Fig. 7A. A pair of guide pins 22 telescopically and slidingly
connect the pair of cones 18U, 18L to one another and the arms 25U, 25L
and angled recesses 27U, 27L are arranged such that any movement of
the lower cone 18L toward the upper cone 18U will result in radially
outward movement of the slip 19. Furthermore, the respective upper 29U
and lower 29L outward facing surface of the respective cones 18U, 18L is

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
23
tapered at preferably the same angle as the respective angled recess
27U, 27L in order to ease radially outward movement of the slips 19 when
the respective upper and lower ends of the slips 19 meet said outward
facing surface 29.
In turn, the cones 18U, 18L are each provided with their own angled
recesses 31U, 31L in their outer side faces and which are arranged to
engage with angled arms 33U, 33L provided on the respective upper 20
and lower 17 cone expanders such that any movement of the lower cone
expander 17 toward the upper cone expander 20 will result in longitudinal
movement of the cone 18L toward the upper cone 18U. Furthermore,
once the lower cone 18L has travelled sufficiently in the longitudinal
direction to butt against the upper cone 18U (such that the guide pins 22
are entirely contained within the cones 18U, 18L), the interaction between
the angled recesses 31U, 31L and angled arms 33U, 33L will result in
radially outward movement of the cones 18U, 18L and will thus result in
even further radial outward movement of the slips 19. Thus, a much
greater radial outward movement of the slips 19 is possible with the slip
section 40 than compared with conventional slip sections and thus a high
expansion slip system 40 is provided. Again, as most clearly shown in Fig.
7A, the outward facing surfaces 35U, 35L provided at the ends of the
respective cone expanders 20, 17 are also tapered in a direction from
radially inner most to radially outer most away from each other and said
tapered outward facing surfaces 35U, 35L help promote radially outward
movement of the cones 18U, 18L when their respective ends meet said
surfaces 35U, 35L.
It should be noted that whilst the angles of the tapered surfaces 35U, 33U,
31U (and the other respective surfaces for the lower cone 18L) are
preferably all the same, they need not be the same as the tapered

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
24
surfaces 29U, 27U, 25U and in the embodiments shown in Fig. 7A they
are indeed not the same because it is preferred to have a steeper angle of
200 (to the longitudinal axis of the slip section 40) acting between the slip
19 and the cone 18 (compared to a shallower angle of 15 between the
cone 18 and the cone expanders 17, 20) in order to promote radial
outward movement of the slip 19 first and then have movement in a radial
outward direction of the cones 18U upon further longitudinal movement of
the cone expander 17 towards the upper cone expander 20. However, it
may in some other applications that it would be preferred to move the
cones 18 outwards first before then moving the slips 19 with respect to the
cones and in such a situation, the angle between the slip 19 and the cone
18 is shallower than the angle between the cone 18 and the cone
expanders 17, 20.
Embodiments of the high expansion slip system in accordance with the
first aspect of the present invention such as the slip section 40 can be
used in any situation where an operator requires to transfer loads into a
formation to for instance hang a load off a formation such as hanging off
casing or tubing for production, injection or for the purpose of stimulation
of the well or for any other application where it is desirable to anchor the
tubing/casing. By anchoring the tubing/casing, relative movement and
loads are confined to the anchor points.
It should be noted that whilst the slips section 40 is actuated by the setting
section 60 and locking section 50 in the preferred embodiment disclosed
in the drawings, other embodiments of slips section 40 could be actuated
by different types of setting sections for instance by hydraulic, hydrostatic
or electrical downhole motors.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
Setting Section 60
The setting section 60 is a mechanical setting section and comprises a
bottom sub 1 securely screw threaded at its upper end to the lower end of
5 a mandrel 3. A sleeve stop 2 is securely screw threaded into the inner
surface of the bottom sub 1 and serves to act as a stop to shift sleeve 4 as
will subsequently be described.
A shift sleeve 4 is also provided on the interior of the mandrel 3 and were
10 it not for shear screw 8, inner interlock key 7 and setting load key 5,
the
shift sleeve 4 would be freely moveable in the mandrel 3. However, a
shear screw 8 (initially at least) locks the shift sleeve 4 with respect to
the
cone mandrel 23. However, if a mechanical shifting tool (not shown) is run
into the well bore and engages the shifting profile 37 and is pulled with
15 sufficient force in the upward direction (left to right in e.g. Fig. 1
E) the
shear pin 8 will fail and be sheared. At this point, it is important to note
that the inner most surface of the inner interlock key 7 is screw threaded to
the outer surface of the shift sleeve 4 and the outer surface of the outer
interlock key is screw threaded to the inner surface of a setting sleeve 9.
20 The outer surface of the inner interlock key has at least one and, as
shown
in Fig. 5D, preferably has three upset ridges which sit upon three inwardly
projecting upset ridges provided on the inner most surface of the outer
interlock key 6. Consequently, whilst the inner and outer interlock keys 7,
6 are in the configuration shown in Fig. 5D, the inner interlock key 7 is
25 screw threaded to the shift sleeve 4 and more importantly the setting
sleeve 9 is screw threaded to the outer interlock key 6. Because the outer
interlock key 6 is the same length as the aperture within which it sits, this
means that the setting sleeve 9 cannot move. However, once the shear
screw 8 has ruptured, longitudinal movement of the inner interlock key 7
can occur with respect to the outer interlock key 6 until the three upset

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
26
ridges clear one another at which point the inner 7 and outer 6 interlock
keys can collapse in on one another thus breaking the respective screw
threaded connections with the shift sleeve 4 and the setting sleeve 9.
The setting or load key 5 comprises a number of inwardly projecting ridges
42 which can move back and fore within corresponding outwardly
projecting ridges 43 provided on the outer surface of the shifting sleeve 4
and it should be noted that the distance between the outwardly projecting
ridges 43 on the shifting sleeve 4 is greater than the distance required for
the ridges of the inner 7 and outer 6 interlock keys to clear one another.
Accordingly, once the inner 7 and outer 6 interlock keys have collapsed in
on one another, any continued upward movement of the shift sleeve 4 will
result in the outwardly projecting ridges 43 butting against the inwardly
projecting ridges 42 of the load setting key 5 and thus the load setting key
5 will be carried upwards with the shift sleeve 4. It should be noted that
the load key 5 is located in a longitudinal slot within the mandrel 3/cone
mandrel 23 and thus because the load key 5 is screw threaded to the
inner surface of the setting sleeve 9 at the lower end of the setting sleeve
9, any continued upward pulling of the shifting tool (not shown) will result
in upward movement of the shift sleeve 4, the load key 5 and the setting
sleeve 9.
The setting section 60 when used in conjunction with a mechanical set
slips anchor 100 such as the preferred embodiment slip section 40 proves
particularly advantageous in horizontal wells because the setting section
60 provides the feature of being able to positively lock the shift sleeve 4 to

the rest of the tool 100. In addition to this, the setting section 60 will be
able to withstand a high load on the outside of it (as experienced when
running the tool 100 in the hole) without activating, whilst a low load will
be
required to trigger the setting section 60 from the inside of the tool 100

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
27
(when the shifting tool shifts the sleeve 4). Accordingly, the setting
mechanism in the form of the setting sleeve 9 on the outside of the tool
100 is mechanically locked until the internal shift sleeve 4 is manipulated
by the shifting tool. This is particularly advantageous in horizontal wells as
the drag on the tool 100 running in the well will not pre-set the tool 100
(which can happen with conventional tools without such a setting section
60).
Locking Section 50
The locking section 50 is best shown in Fig. 1C which shows the running
in and pre-actuation configuration and in Fig. 2C which shows the post
actuation or set configuration. The locking section 50 comprises a C-
shaped reduced backlash lock ring 15 in accordance with the third aspect
of the present invention and as best seen in Figs. 6A-6E. As shown in Fig.
6A, the lock ring 15 is near circular but comprises a notch 45 provided
therein at a point around its circumference such that the lock ring 15
covers in the region of 350-359 . Accordingly, the lock ring 15 can be
compressed slightly to reduce its diameter if required. As can also be
seen in Fig. 6A, the lock ring 15 comprises a right angled saw tooth 47 on
its outer circumference having a pitch in the region of 8 TPI (0.125" pitch)
and further comprises a much finer right angled saw tooth 49 formed on its
inner circumference which is in the region of 16-32 TPI (0.031" to 0.062"
pitch).
The lock ring 15 is placed around the relatively smooth outer
circumference of the cone mandrel 23 such that its outer right angled saw
toothed thread profile 47 engages with an inwardly projecting and
corresponding right angled saw tooth thread profile provided on an inner
circumference of the lower end of an adjustor sub 16 which is fixedly

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
28
screw threaded to the lower end of the lower cone expander 17. A load
ring 13 is butted up against the lower end of the reduced back lash lock
ring 15 by means of a wave spring 11 and spring washer 12 arrangement
that acts to bias the load ring 13 against the lock ring 15 and in practice
tries to push the lock ring 15 upwards (from right to left in Fig. 1C) with
respect to the adjustor sub 16.
A connector 14 is placed around the outer circumference of the lower end
of the adjustor sub 16 and is threaded onto the upper end of the setting
sleeve 9 by means of co-operating screw threads 51 as best seen in Fig.
1D. By adjusting this thread the adjuster sub 16 is driven into the lock ring
in order to pre-load the lock ring 15 which in turn compresses the wave
springs 11. This is to ensure that there is a constant spring load exerted
onto the flank angles of the pitch profile on the outside edge of the lock
15 ring 15 and the inside profile of the adjuster sub 16.
As shown in Fig. 1D, a flat head screw 10 projects radially inwardly from
the setting sleeve 9 and projects into a longitudinally arranged slot 24
formed in the cone mandrel 23 such that whilst the flat head screw 10 is
located in the longitudinally arranged slot 24, the setting sleeve 9 is
prevented from rotating with respect to the cone mandrel 23. As
previously described, the shifting tool (not shown) is used to pull the
setting sleeve 9 upwards with great force and this acts upon the load ring
13 via the wave spring 11 to move the lock ring 15 up the outer surface of
the cone mandrel 23.
With conventional lock rings, typically a right angled saw tooth ratchet
mechanism would be formed on the outer surface of the cone mandrel 23
to interact with the inner surface of the lock ring such that the lock ring
"climbs" up the ratchet mechanism provided on the cone mandrel 23.

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
29
However, the lock ring 15 of the present invention provides the great
advantage that it does not require a ratchet mechanism to be formed on
the outer circumference of the cone mandrel 23. In fact, the outer surface
of the cone mandrel 23 can be simply lightly roughened (for instance with
some scratches provided on its outer surface) or even just left smooth
because the lock ring 15 of the preferred embodiment is formed from a
very hard material such as nitrided steel such as 50 Rockwell C compared
to a softer steel such as for instance 20 Rockwell C steel for the cone
mandrel 23 and because the inner circumference of the lock ring 15 has a
much finer right angled saw tooth ratchet mechanism compared to
conventional lock rings, the inner circumference of the lock ring 15 will bite

or dig into the outer circumference of the cone mandrel 23 as it is moved
up the cone mandrel 23. Alternatively or in addition, the material of the
lock ring 15 may be surface treated to provide the teeth 49 with at least an
outer surface formed from a harder material than the material of the cone
mandrel 23.
The right angled saw tooth form of the outer circumference of the lock ring
15 is a tapered thread form which spreads the load across the length of
the lock ring 15 in use. The flank angle of the outer right angle saw tooth
thread form on the lock ring 15 is typically in the region of 20 degrees
which is shallow enough so that when a given axial load is exerted on it, it
reduces the required amount of inward radial load to initiate the hardened
(much finer) saw tooth profile on the inside of the lock ring 15 to bite onto
the mandrel 23.
It is this ability to exert a constant load onto the flank angle that provides

great advantages to embodiments of the present invention and therefore
the only backlash exerted by the lock ring 15 is the backlash that is
induced when the hardened inner teeth "bite" into the mandrel 23.

CA 02748672 2011-06-30
WO 2010/084353 PCT/GB2010/050093
Figs. 8A-8E show a preferred embodiment of a reduced backlash lock ring
150 in accordance with the third aspect of the present invention and Fig.
1DB shows the lock ring 150 located in situ within the tool 100. The lock
5 ring 150 of Figs. 8A-8E is preferred to the lock ring 50 of Figs. 6A-6E
for a
number of reasons.
The lock ring 150 has three main sections:-
i) lock ring section 152 comprising at least one saw tooth 147
10 thread profile formed on its outer circumference ¨ as shown in the
Figs.,
there are two such teeth 147. The lock ring section 152 also comprises a
much more shallow and finer at least one right angled saw tooth 149
formed around its inner circumference (there are three such right angled
saw teeth 149 shown on the embodiment of Figs. 8A-8E). The lock ring
15 section 152 comprises a number of castellated tongues 151 equi-spaced
around its circumference as will be described subsequently;
ii) spring section 154 comprising a repeating S-shaped spring
and which in use will perform the same function as the load ring 13 and
wave springs 11 of the less preferred load ring 15; and
20 iii) screw threaded section 156 which comprises a complete
circular annular ring 157 and which on the outer surface thereof is formed
a screw thread 158 to enable the lock ring 150 to be screw threaded to
(and thereby secured directly to) the lower end of the adjustor sub 16.
25 The lock ring 150 is located around the relatively smooth outer
circumference of the cone mandrel 23 such that its outer saw tooth thread
profile 147 engages with an inwardly projecting and corresponding saw
tooth thread profile 148 provided on the inner circumference of the lower
end of the adjustor sub 16 (which again is fixedly screw threaded to the
30 lower end of the lower cone expander 17). Depending upon the extent

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
31
that the lock ring 150 is screwed into the lower end of the adjustor sub 16
via the threads 158, will determine how much pre-loading is included into
the spring section 154 in order to bias and thereby push the lock ring
section 152 upwards (from right to left in Fig. 1DB with respect to the rest
of the adjustor sub 16). This again ensures that there is constant contact
between the flank angles 148F and 147F during operation or actuation of
the lock ring 150 and moreover ensures a constant spring load exerted
onto the flank angles 147F of the pitch profile 147 on the outer
circumference of the lock ring 150 and the flank angles 148F provided on
the inside profile 148 of the adjustor sub 16.
Again, the outer surface of the cone mandrel 23 can be simply lightly
roughened (for instance with some scratches provided on its outer
surface) or even just left smooth because the lock ring 150 of the preferred
embodiment is formed from a very hard material, typically nitrided steel
having a hardness of 50 Rockwell C or greater (compared to the softer
steel of the cone mandrel 23 which may be in the region of 18 to 22
Rockwell C hardness). Again, alternatively or in addition, the material of
the lock ring 150 may be surface treated to provide the teeth 149 with at
least an outer surface formed from a harder material than the material of
the cone mandrel 23.
In any event there is preferably a difference of at least 20 Rockwell C
between the hardness of the teeth 149 and the hardness of the cone
mandrel 23.
Furthermore, the teeth 149 have a lead face 149L which is relatively
shallow (the lead face 149L typically has an angle in the region of 30
degrees radially outwardly in the direction from left to right of Fig. 1DB of
the longitudinal axis of the lock ring) which will tend to lift the teeth 149

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
32
radially outwardly when the lock ring section 152 moves up the cone
mandrel 23 during actuation.
In addition, the mating faces of the thread profiles 148T, 147T are
preferably arranged at 800 (radially outwardly in the direction from left to
right of Fig. 1DB of the longitudinal axis of the lock ring 150) in order to
provide a back angle to the thread profiles 148T, 147T and this provides
an advantage during assembly of the lock ring 150 onto the cone mandrel
23. During assembly, the lock ring 150 is initially screwed relatively far
into the lower end of the adjustor sub 16 via the threads 158 such that the
flank faces 147F and 148F are compressed together due to compression
in the spring section 154. The end of the lock ring 150 beside the screw
threads 158 is then rotated in the reverse direction such that the
compression in the spring section 154 is removed and instead tension is
induced in the spring section 154. This causes the flank angles 147F,
148F to move apart and, instead, the back angles 148T, 147T will come
into contact with one another. This causes the lock ring section 152 to
open up or be moved radially outwardly such that the teeth 149 are clear
of the cone mandrel 23. Accordingly, the presence of the back angles
148T, 147T and the contact therebetween enables the setting sleeve 9
and adjuster sub 16 with the lock ring 150 to then be slid down the cone
mandrel 23 during the next stage of assembly of the tool 100 (such
downward movement (from left to right in Fig. 1DB) normally being
prevented during the actuation stage of operation) until the inner
circumference of the threaded end 158 of the lock ring 150 sits over a key
159 which prevents rotation of the lock ring 150 with respect to the cone
mandrel 23. The final step of the assembly of the lock ring section 150 is
completed by rotating the setting sleeve 9 and the adjuster sub 16 with
respect to the cone mandrel 23 and hence the lock ring 150 such that the
setting sleeve 9 and the adjuster sub 16 move downwards (from left to

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
33
right in Fig. 1DB) with respect to the stationary cone mandrel 23 to remove
the tension in the spring section 154 such that the connection between the
back angles 148T and 147T is removed (this is the exact configuration
shown in Fig. 1DB) and further until compression is induced in the spring
section 154 such that the connection between the flank angles 148F and
147F is provided. The lock ring section 150 is thus ready for actuation.
Accordingly, the back angles and their contact during the assembly of the
tool 100 aid free movement of the lock ring section 152 in the assembly of
the tool 100 but play no part in the operation of the lock ring 150 during
actuation thereof and thus the lock ring 150 only allows movement in one
direction (i.e. from right to left in Fig. 1DB) and prevents movement of the
setting sleeve 9 in the downwards or reverse direction (from left to right in
Fig. 1DB) during the actuation stage of the tool 100. In other words, it
should be noted that the possibility of free movement for the lock ring 150
as shown for example in Fig. 2DB from left to right is for assembly
purposes only and that, when the anchor 100 is installed and the spring
section 154 is compressed, movement of the setting sleeve 9 and adjustor
sub 16 from left to right when compared to the stationary cone mandrel 23
will be stopped by the anchor 100, while movement from right to left of the
setting sleeve 9 and adjustor sub 16 when compared to the stationary
cone mandrel 23 is allowed.
Furthermore, the inner teeth 149 will tend to bite into or dig into the outer
circumference of the cone mandrel 23 whenever the lock ring section 152
stops moving up the cone mandrel 23. Furthermore, when the load being
exerted by the setting sleeve 9 reduces or is removed, the adjustor sub 16
will be prevented from moving downwards (with respect to the cone
mandrel 23/string of tubulars or upwards as shown in Fig. 1DB when
viewing it in portrait or from left to right when viewing Fig. 1DB in
landscape and any attempted movement of the adjustor sub 16

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
34
downwards with respect to the cone mandrel 23 means that the flank
angles 148F of the thread profiles 148 will force the flank angles 147F of
the thread profile 147 radially inwardly thereby digging the inner teeth 149
even further into the cone mandrel 23 and further preventing such
downwards movement of the adjustor sub 16 with respect to the cone
mandrel 23.
Preferably, the flank angles 147F, 148F are in the region of 20 to the
longitudinal axis of the tool 100 and this provides the advantage that this
relatively shallow angle requires less force to push the teeth 149 into the
cone mandrel 23 than an otherwise greater angle would require.
As can be seen in Fig. 8A, the lock ring section 152 and spring section
154 are slotted or castellated in order to allow the individual tongues 151
(as shown in Fig. 8A there are six in the embodiment of lock ring 150) to
move radially inwardly as required in order to bite into the cone mandrel
23. Furthermore, it should be noted that the inner diameter of the lock ring
section 152 and spring section 154 is ever so slightly smaller than the
outer diameter of the cone mandrel 23 (although the inner diameter of the
threaded section 156 is a close fit with or is just slightly larger than the
outer diameter of the cone mandrel 23) and this provides the advantage
that the outer edges of the teeth 149 on each tongue 151 will tend to bite
into the cone mandrel 23 first and then the rest of the teeth 149 (i.e. in
between the outer edges of each tongue 151) will then bite into the cone
mandrel 23 and this provides a better engagement between the teeth 149
and the cone mandrel 23.
Consequently, embodiments of the third aspect of the present invention
provide the advantage that they provide much reduced back-off or back
lash compared to conventional lock rings when the actuation force is

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
removed and thus greater force can be maintained with the tool to which
the locking section 50 is attached which in this case is a slip section 40 but

could be for instance a packer mechanism or the like.
5 Accordingly, embodiments of the third aspect of the present invention
have the advantage that, because the lock ring 15, 150 is preloaded with
the spring 11, 154, this eliminates the back lash that would conventionally
be experienced on the outer thread profile. Furthermore, because there is
no inner ratchet mechanism for the inner teeth 49, 149 to jump, the back
10 lash that would conventionally be experienced with conventional lock
rings
has been eliminated. It is believed that embodiments of the reduced back
lash ring in accordance with the third aspect of the present invention will
prove very beneficial to a wide variety of applications (downhole oil & gas
related and non downhole) where a reduced backlash one way movement
15 mechanism is required. Potential downhole oil and gas applications
include setting of metal to metal seals (since these require relatively high
setting forces and conventional lock rings with reasonably high backlash
can be unreliable when setting them because the setting forces may be
achieved but can then be lost when the backlash occurs), packers, bridge
20 saddles, slips (such as the example given herein) liner hangers and
others.
Modifications and improvements may be made to the embodiments
hereinbefore described without departing from the scope of the invention.
For instance, the setting sleeve could be modified to allow a releasing
shearing feature once a set load has been applied and this will allow the
shift sleeve 4 to stroke fully and release the shifting tool (not shown). In
this modification, an interlock may be required to transfer initial setting
forces through a path other than the releasing shear screws to avoid initial

CA 02748672 2011-06-30
WO 2010/084353
PCT/GB2010/050093
36
shearing of the screws as the initiation screws fail in the shift sleeve 4.
This feature would disengage once a small amount of travel has been
made by the setting sleeve 4.
10

Representative Drawing